Automatic choke



Ndv. 1, 1932. D. COLLINS ,88

AUTOMATIC CHOKE Filed Nov. 5, 1929 2 Sheets-Sheet 1 ZSmaentor ZQUGL/IS COLL/IVS (I ttorneg Nov. 1, 1932. D. COLLINS 1,385,331 AUTOMATIC cnoxs Filed Nov. 5, 1929 2 Sheets-Sheet 2 JOUGL/IS COLL/A's Zhwentor Gftorneg Patented Nov. 1, 1932 PATENT OFFICE DOUGLAS COLLINS, or SALISBURY, NORTH CAROLINA AIITOMATIC CHOKE Application filed November 5, 1929. Serial No. 404,996.

' My present invention relates'to an automatic choke employing fluid pressure in its operation and the choke is designed for use with internal combustion engines, especially those employed on automotive vehicles, water craft, and air craft. a I

In carrying out my invention I utilize pressure in a stream of exhaust gases extracted from'the exhaust manifold of the motor, and apply the pressure directly to the choke valve or valve that controls and regulates the admission of air to the carbureter of the internal combustion engine.

In actual practice of my invention the choke valve is retained, as by a weight, in closed position and remains idle when the engine or motor is not running; but during the operation of the motor and while the exhaust gases are passing through the exhaust mania.

fold, the choke valve is automatically operated under the varying pressures of the exhaust gases.

In this manner the fuel mixture is diluted by the air passing to thecarbureter and the admission of air is automatically regulated and controlled in response to the varying con- 'ditions required of the. fuel mixture.

The automatic choke valve may be adjusted so that while the motor is runningat idling speed and above that speed, the choke regulates the dilution of the fuel mixture from a rich fuel charge to a thin fuel charge. Should the charge become too thin, or the fuel supply dwindle to the minimum feed the pressure of the exhaust gases then becomes insufficient to retain the choke valve in open position, whereupon the valve is automaticall closed. V

I preferably utilize a gravity operated,

pivoted, choke valve having a weight of ample proportions to hold the valve closed in the absence of pressure from the exhaust gases, and my invention is readily adapted for use with the customary butterfly type of choke valve, as used upon standard automotive vehicles, as well as for use with other types of valves.

' The primary object of. my invention is the provision'of a device which operates to .enrich the mixture at the proper time and in the motor is operating. My automatic'choke deproper proportions, under varying pressures of the exhaust gases for the purpose of economizing in the consumption of fuel, limiting the usual manual control for the choke valve and for insuring against over-choking and its. attendant harmful results.

The invention consists in certain novel combination and arrangements. of parts as will hereinafter be more fully set forth and claimed. 7 Q9;

In the accompanying drawings I have shown two forms of the physical embodiment of my invention inwhich I employv a mini mum number of parts to insure simplicity in manufacture, convenience in assembling the devices for use, and simplicity in the opera tion of the device. 7 U V While the drawings illustrate the parts combined and arranged according to'modes that have proven satisfactory'and successful in operation, it willbe understood that various changes, within the scope of my claims, may be made without departing from the principles of the invention.

Figure :1 is a perspective view indicating the necessary parts of a motor for illustrating the application of my invention.

Figure 2 is a face view of the preferred form of the automatic choke with the valve closed. V l I I Figure 3 is a sectional detail view at'line 3-3 of Figure 2. v

Figure 4 is a face view of the automatic choke device with the valve wide open.

' Figure 5' is aside view of a different form of the automatic chokewith the valve closed.

Figure 6 is a sectional detail view of the device of Figure 5 with the butterfly valve open under pressureof exhaust gas.

Figure 7 is a face view of Figures 5 and 6.

In the assembly view, Figure 1, I have indicated a motor 1 with its carbureter 2 and the usual air pipe 3. The intake manifold is designated 4 and the exhaust manifold is indicated as 5, a pressure pipe6 being connected to the exhaust manifold at 7 for the purpose of extracting a stream of exhaust gases from the exhaust manifold while the the device in vice is applied directly to the air pipe 3 and preferably on the end thereof.

In carrying out my invention in its preferred form I use a casing or cup-shaped casting 8 which is fashioned with a laterally extending nipple 9 having a port 10. This cup 8 is fashioned with a reduced annular flange 11 which fits over the end of the air pipe 3, and set bolts 12 are used to clamp the cup on the pipe 3. In this manner the carbureters employed in connection with existing motors may quickly be equipped with the device of my invention.

Within the circular cup 8, I provide a partition 13 having a number of spaced openings or holes 14: therein. The partition is fashioned with a central boss 15 that projects at the outer side of the partition and upon this boss is mounted the choke valve 16. The choke valve is preferably trefoil in form and complementary to thethree openings or holes in the partition 13. The valve is fashioned with a bearing sleeve 17 that is rotatable on the boss 15, and a nut 18 on the threaded end of the boss holds the rotatable valve against displacement.

The trefoil valveis preferably gravity operated, and for this purpose one of the sections of the valve is fashioned witha weight 16 of suflicient proportions to hold the valve in'closed position as in Figures 2 and 3.

One of the sections of the trefoil valve is provided with a plurality of laterally extending vanes 19 that are arranged on spaced radial lines and in position to receive pressureof exhaust gases from the port 10. As seen; in Figure 4: where the valve is shown wide open, the stream of exhaust gas passing through the port 10 has impinged suc cessively on the several vanes and turned the valveto wide open position. The valve is thus operated in manner similar to the operation of a. turbine. The varying pressure of the exhaust gases on the valve and the weight 16' of the valve thus maintain the valve in pro-per position to control and regulate the admission of air to the pipe 3 in proportion as the air is neededinthe-fuel mixture. The rotary valve is limited in its movement by the use of a pin- 20 on the partition and a notch 21 in the edge of one of the valve sections, and the range of movement is thus limited as indicated in- Figures 2 and 4.

It will be apparent that the trefoil valve 16 is retained in closed position due to gravity and the use of the weight 16. As the exhaust gases pass through the exhaust inanifold and into the pressure pipe 6, it will be apparent that the impingement of the gases onthe first vane 19 will overcome the inertia of the valve and turn the latter anti-clock wise. As the pressure increases in the exhaust gases, the trefoil valve is further moved by impingement of the gases against the successivevanes. By the employment of a number of spaced vanes it will be apparent that the pressure is applied more efliciently to the valve than would be the case where only one vane is employed.

In the modified form of my invention as disclosed in Figures 5, 6 and 7, the device includes a cap 22 in which is mounted a nozzle 23. This nozzle is connected with the pressure pipe 6 and also with the exhaust manifold. The nozzle is adjustable in a boss 2 L that is fashioned integrally with the top wall of the cap 22 and a set screw or bolt 25 is used to clamp the nozzle in adjusted position. Within the cap is pivoted a butterfly valve 26 .and as indicated by the arrows, the pressure of the exhaust gases passing through the nozzle 23 causes the movement of the valve 26. The valve 26 is also closed by the action of'gravity and for this purpose a weight 27 isprovided for the lower part of the pivoted valve so that in the absence of pressure in the nozzle 23 the valve 26 remains in closed position as in Figures 5 and 7 The cap 22 is attached to the end of the air pipe 3 and secured thereon by the screws or bolts 12.

The valve 26 is adjustably supported in the cap 22 so that its pivotal point may be raised or lowered for the purpose of varying its movement on the pivot The pivot is formed of a slotted bar 28 in which the flat disk form- -ing the valve 26 is secured and the opposite ends of this bar 28 are reduced to form trunnions 29, and the ends of the trunnions are threaded to receive clamp nuts 30.-

The trunnions are journalled in bearings 32 located on the exterior faces of the arms of a U-shaped yoke 31. This yoke is slipped over the top of the cap down its sides in complementary grooves 33 and is supported: by a set screw 34L- passing through the. cross bar of the yoke, and impinging against the top face of the cap. The slotted bar passes through slots 35 in the side walls of the cap and it will be apparent that these slotted walls permit vertical adjustment of the yoke and of the choke valve 26 which is supported in the yoke. The grooves 33 extend diagonally across the outerfaces of the cap 22 and the choke valve 26 may be raised or lowered by use of the bolt 34 for the purpose of adjusting the valve within the open end of the cap.

From the above description taken in connection with my drawings, it will be appar cut that T have provided an automatic choke device which is simple in construction and operation and is efiicient in the performance of its functions.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a charge forming device for an internal combustion engine, the combination with an air feed pipe, of a choke device for the ice air pipe comprising a casing and its regulating valve, and means for introducing pressure of exhaust gas against said valve for opening the latter.

2. A charge forming device for an internal combustion engine comprising a valve cas-' ing, a valve in the casing and automatic means for closing said valve, and means for introducing varying pressures of exhaust gases against said valve for opening the latterr 3. In a charge forming device for an internal combustion engine, the combination with an air feed pipe, of a choke device comprising a casing and its gravity closed pivoted valve,

and means for introducing pressure of exhaust gas against said valve in opening the latter.

4. A charge forming device for an internal combustion engine comprising a valve casing, a counter-Weighted valve pivoted in the casing, and means for introducing varying pressures of exhaust gases against said valve for opening the latter. I

DOUGLAS COLLINS. 

